• Journal of Aerospace System Engineering
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• v.12 no.1
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• pp.47-56
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• 2018

In this paper, the structural analysis of the Geostationary Korea Multi-Purpose Satellite-2 (GEO-KOMPSAT-2) tubing system is discussed, and the structural integrity of the tubing system is assessed by comparative analysis with the results of overseas partner AIRBUS. Securing structural reliability of the tubing system is a very important key element of the propulsion system of the GEO-KOMPSAT-2 satellite. Therefore, FE modeling of the propulsion tubing was carried out directly using the CAE program, and structural analysis was performed to evaluate the stress state under launch conditions. Hoop stress, axial stress, bending stress, and torsion stress were calculated according to diverse load conditions by using pressure stress analysis, thruster alignment analysis, sine qualification load analysis, and random qualification load analysis. From the results, the Margin of Safety (MoS) of the tubing system is evaluated, and we can verify the structural integrity of the tubing system when subjected to various launch loads.

• Journal of the Korean Society of Safety
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• v.36 no.1
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• pp.18-25
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• 2021

In many developed countries, such as South Korea, efficiently maintaining the aging infrastructures is an important issue. Currently, inspectors visually inspect the infrastructure for maintenance needs, but this method is inefficient due to its high costs, long logistic times, and hazards to the inspectors. Thus, in this paper, a novel crack inspection approach for concrete bridges is proposed using integrated image processing techniques. The proposed approach consists of four steps: (1) training a deep learning model to automatically detect cracks on concrete bridges, (2) acquiring in-situ images using a drone, (3) generating orthomosaic images based on 3D modeling, and (4) detecting cracks on the orthmosaic image using the trained deep learning model. Cascade Mask R-CNN, a state-of-the-art instance segmentation deep learning model, was trained with 3235 crack images that included 2415 hard negative images. We selected the Tancheon overpass, located in Seoul, South Korea, as a testbed for the proposed approach, and we captured images of pier 34-37 and slab 34-36 using a commercial drone. Agisoft Metashape was utilized as a 3D model generation program to generate an orthomosaic of the captured images. We applied the proposed approach to four orthomosaic images that displayed the front, back, left, and right sides of pier 37. Using pixel-level precision referencing visual inspection of the captured images, we evaluated the trained Cascade Mask R-CNN's crack detection performance. At the coping of the front side of pier 37, the model obtained its best precision: 94.34%. It achieved an average precision of 72.93% for the orthomosaics of the four sides of the pier. The test results show that this proposed approach for crack detection can be a suitable alternative to the conventional visual inspection method.

• Korean Journal of Occupational Health Nursing
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• v.11 no.1
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• pp.13-30
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• 2002

Industrial shift workers feels suffer mental stresses which are caused by unfamiliar day sleep, noisy environment, sleeping disorder by bright light, unusual contacts with family, difficulty in meeting with friends or having formal social meetings and other social limitations such as the use of transportation. Such stresses influence health of the workers negatively. Thus the health promotion policy for shift workers should be made considering the workers' ways of living and shift work specially. This study attempted to provide basic information for development of the health promotion program for industrial shift workers by examining predictive factors influencing health promotion behaviors of those workers. In designing the study, three power generation plants located in Pusan and south Kyungsang province were randomly selected and therefrom 280 workers at central control, boiler and turbine rooms and environmental chemistry parts whose processes require shift works were sampled as subjects of the study. Data were collected two times from September 17 to October 8, 1999 using questionnaires with helps of safety and health managers of the plants. The questionnaires were distributed through mails or direct visits. Means for the study included the measurement tool of health promotion behavior provided by Park(1995), the tool of self-efficacy measurement by Suh(1995), the tool of internal locus of control measurement by Oh(1987), the measurement tool of perceived health state by Park(1995) and the tool of social support measurement by Paek(1995). The collected data were analyzed using SPSS program. Controlling factors of the subjects were evaluated in terms of frequency and percentage ratio Perceived factors and health promotion behaviors of the subjects were done so in terms of mean and standard deviation, and average mark and standard deviation, respectively. Relations between controlling and perceived factors were analyzed using t-test and ANOVA and those between perceived factors and the performance of health promotion behaviors, using Pearson's Correlation Coefficient. The performance of health promotion behaviors was tested using t-test, ANOVA and post multi-comparison (Scheffe test). Predictive factors of health promotion behavior were examined through the Stepwise Multiple Regression Analysis. Results of the study are summarized as follows. 1. The performance of health promotion behaviors by the subjects was evaluated as having the value of mean, $161.27{\pm}26.73$ points(min.:60, max.:240) and average mark, $2.68{\pm}0.44$ points(min.:1, max.:4). When the performance was analyzed according to related aspects, it showed the highest level in harmonious relation with average mark, $3.15{\pm}.56$ points, followed by hygienic life($3.03{\pm}.55$), self-realization ($2.84{\pm}.55$), emotional support($2.73{\pm}.61$), regular meals($2.71{\pm}.76$), self-control($2.62{\pm}.63$), health diet($2.62{\pm}.56$), rest and sleep($2.60{\pm}.59$), exercise and activity($2.53{\pm}.57$), diet control($2.52{\pm}.56$) and special health management($2.06{\pm}.65$). 2. In relations between perceived factors of the subjects(self-efficacy, internal locus of control, perceived health state) and the performance of health promotion behaviors, the performance was found having significantly pure relations with self-efficacy (r=.524, P=.000), internal locus of control (r=.225, P=.000) and perceived health state(r=.244, P=.000). The higher each evaluated point of the three factors was, the higher the performance was in level. 3. When relations between the controlling factors(demography-based social, health-related, job-related and human relations characteristics) and the performance of health promotion behaviors were analyzed, the performance showed significant differences according to marital status (t=2.09, P= .03), religion(F=3.93, P= .00) and participation in religious activities (F=8.10, P= .00) out of demography-based characteristics, medical examination results (F=7.20, P= .00) and methods of the collection of health knowledge and information(F=3.41, P= .01) and methods of desired health education(F=3.41, P= .01) out of health-related characteristics, detrimental factors perception(F=4.49, P= .01) and job satisfaction(F=8.41, P= .00) out of job-related characteristics and social support(F=14.69, P= .00) out of human relations characteristics. 4. The factor which is a variable predicting best the performance of health promotion behaviors by the subjects was the self-efficacy accounting for 27.4% of the prediction, followed by participation in religious activities, social support, job satisfaction, received health state and internal locus of control in order all of which totally account for 41.0%. In conclusion, the predictive factor which most influence the performance of health promotion behaviors by shift workers was self-efficacy. To promote the sense, therefore, it is necessary to develop the nursing intervention program considering predictive factors as variables identified in this study. Further industrial nurses should play their roles actively to help shift workers increase their capability of self-management of health.

• Proceedings of KOSOMES biannual meeting
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• 2007.11a
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• pp.61-67
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• 2007

With an entering into force of OPRC-HNS started in June 14th 2007, establishment of response system in a nationwide scale to take care of accidents is required to respond rapidly and effectively. This necessities drove us to analyze national contingency plan for chemicals including national response system against accidents, which is in operation in the US. Main characteristics of the system are well described as an integrated incident command system with a cooperation of responsibilities facilities, manpower, and technical support. In addition, state anψor local authorities tend to have responsibilities on management of disaster with its response activities. Polluters are also charged to pay expenses 3 times expensive provided state or local authorities are conducted. In general, response activities are conducted by private sectors. However, the government will take action with Superfund if the response capacity is over than the polluters can. However, safety are regarded as a primary factor to be considered in the response activities, and try not to recover any pollutants. Personals belonging to USCG and EPA are required to complete specialized courses to promαe professional skills, and are also welcomed to participate in "certification program"

• Journal of Korean Society of Steel Construction
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• v.13 no.5
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• pp.567-575
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• 2001

In order to consider statistical properties of probability variables used in the structural analysis the conventional approach using the safety factor based on past experience usually estimated the safety of a structure Also the real structures could only be analyzed with the error in estimation of loads material characters and the dimensions of the members. But the errors should be considered systematically in the structural analysis Safety of structure could not precisely be appraised by the traditional structural design concept Recently new aproach based on the probability concept has been applied to the assessment of structural safety using the reliability concept Thus the computer program by the Probabilitstic FEM is developed by incorporating the probabilistic concept into the conventional FEM method. This paper estimated for the reliability of a plane stress structure by Advanced First-Order Second Moment method using von Mises, Tresca and Mohr-Coulomb failure criterions. Verification of the reliability index and failure probability of attained by the Monte Carlo Simulation method with the von Mises criterion were same as PFEM, but the Monte Carlo Simulation were very time-consuming. The variance of member thickness and load could influence the reliability and failure probability most sensitively among the design variables from the results of the parameter analysis. The proper failure criterion according to characteristic of materials must be used for safe design.

• Journal of Food Hygiene and Safety
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• v.14 no.3
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• pp.293-304
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• 1999

The purpose of this study was to evaluate the microbiological quality, and to assure the hygienic safety of the food production in the university food service facility located in Seoul in accordance with the Hazard Analysis Critical Control Point(HACCP) concepts. In the hygienic state assessment of kitchen, it has revealed that it was very important to remove water from the kitchen floor and to establish standard method for disinfection of cooking utensils. And foodservice workers were required to have training program for the safe handling of food and utensils since they did treat food without hygienic gloves. The kitchen layout had to be improved because the near distance of table with heating unit and shelf might cause the growth of microorganisms when prepared food was kept on the shelf. In terms of the timetemperature measurement and microbiological quality assessment during each of the food production phases, most of sengchae (raw vegetable dish) and namul (cooked vegetable dish) were treated within danger zone for food safeness ($5~60^{\circ}C$). It has shown that the microbiological quality of raw materials was very much inferior at the time of receiving based on the TPC($10^{5}~10^{7}$), coliform($10^{3}~1O^{6}$), which was not acceptable level(TPC:$10^{6}$, coliform:$10^{3}$) suggested by Solberg. Microbiological growth has increased in the both of sengchae and namul considerably during most of food production phase. Therefore, it is extremely important to reduce holding and serving time and to avoid treating food within the danger zone for food safeness. In addition, the prevention of cross-contamination during mixing the ingredients with improper equipments and with insanitary treatments by workers was also important to keep the food safety in this speciqic university foodservice facility.

• The Journal of the Convergence on Culture Technology
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• v.7 no.3
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• pp.509-515
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• 2021

This study analyzes the efficient floor layout plan of classrooms for securing evacuation stability in school in case of fire by using the Pathfinder simulation program. Efficient evacuation methods and safety were evaluated by analyzing REST (Required Safe Egress Time) according to the allocation of personnel by floor targeting a high school 5-story building equipped with a ramp and stairs. The current status of personnel assignments exceeded the Required Safe Egress Time(RSET), resulting in a problem with evacuation safety. When students were placed on the 3rd, 4th, and 5th floors, the result was that the time exceeded RSET the most. When students were placed on the 1st, 2nd, and 3rd floors, the result was that they completed evacuation in the shortest time, less than RSET. In the current state, when evacuation was guided by designating an evacuation exit depending on the location, the result of shortening RSET was obtained. As a result, it is effective to put the students on the lower floors when placing students in high-rise school buildings in terms of evacuation safety, and in the preliminary training, it is required to designate evacuation exits so that they can use the nearest exit for each location in case of a fire. As a future research project, additional research is needed on the RSET when a fire occurs in a specific location according to whether the automatic fire door at that location is opened or closed.

• Journal of forensic and investigative science
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• v.3 no.1
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• pp.60-73
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• 2008

The purpose of Emergency Medical System(EMS) is what a patient returns to society with recovering mental tone in the shortest time as giving prompt and proper medical treatment to patient in emergency situation, and the Correctional Administration(CA) is purposed for the convict to return and settle down to society after release from prison in success as executing schooling, enlightenment activity, vocational training to convict who was quarantined from the society for the term of imprisonment. The EMS and CA will coincide each other which is reverting people to society in safety. This study aims to suggest the developmental program of EMS in correctional facilities through the cause of emergency situation, system, human resources, establishment, medical equipments, state of budget and the point issue for safety of victim who has many chances that is exposed to physical damage and disease because of particularity of lower culture in correctional facilities and the staff who works there. First, in the view of the correctional facility security system, a proper number of the emergency rescuers should be employed. Second, the effective transportation system along with some emergency medical equipment needs to be established. Third, the correctional officers and the prisoners should be learned the first-aid training which is realistic, practical and systematic. Fourth, the cooperative system should be established such as 1339 emergency medical information center in society. Fifth, the Ministry of Health and Welfare must increase EMS budget for correctional facilities.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.11 no.3
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• pp.119-126
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• 2017

In the clinical setting, the pressure bio-feedback device is used for the spinal rehabilitation of patients with back pain, but it has several disadvantages. The purpose of this study was to develop a digitalized pressure biofeedback system that provides precise exercise method and posture in real time during the spinal rehabilitation exercise by sensing and monitoring body movements and balance of users and providing biofeedback to users. After that, the usability testing for a digitalized pressure biofeedback system will be conducted to identify problems such as safety, performance, operability, and satisfaction, and suggest improvement directions. A total of 33 subjects were participated in the usability testing. The experts group and the users group evaluated the developed digitalized pressure biofeedback system on a scale of 5 points after using the equipment. In the user group, safety was 3.59, operability was 4.38, satisfaction was 4.49. In the expert group, safety was 2.86, operability was 3.91, and performance was 4.28. Based on the usability evaluation, if the problems of stability of the cradle for tablet PC, air injection, screen display, etc. are solved, it becomes a exercise device capable of accurately exercising and evaluating the function of the spine by checking its own motion state while the spinal stabilization exercise.

• Journal of Contemporary Eastern Asia
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• v.19 no.1
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• pp.59-83
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• 2020

This paper examines the actions and the factors driving those actions to reduce energy consumption and enhance energy efficiency taken by United States cities. While not much empirical evidence is available on why governments pursue practical sustainability actions, we attempt to shed more light on this important topic by empirically identifying factors that contribute to concrete actions toward sustainability policies. We adopt political market theory as a basic theoretical framework with policy-making applied to city energy consumption. Using the 2010 ICMA (local government sustainability policies and program) data, this study expands the focus of analyses to evaluate the effect of the form of government on energy consumption and energy efficiency by using multiple regression analysis. The findings show that at the city level, the mayor-council form of government are negatively associated with governments' efforts to reduce energy consumption. However, cities with at-large elections and municipal ownership are more likely to adopt sustainability actions. We also find that a large-scale economy has significant effects on the effort to reduce city energy consumption and improve energy efficiency. This shows that environmental policies are directly connected to locally relevant affairs, including housing, energy use, green transportation, and water. Thus, local level administrators could take an executive role to protect the environment, encourage the development of alternative energy, and reduce the use of fossil fuel and coal energy. These efforts can lead to important environmental ramifications and relevant actions by municipal governments.